When a chip card is operated wirelessly, i.e. without galvanically being contacted by a reading device, power for operating the chip card is typically supplied to the chip card by an electromagnetic field emitted by a reading device. While it is desirable to supply sufficient power to the chip card's chip to allow its operation, it may occur that too much power is supplied to chip, e.g. due to the fact that the chip card is brought very closely to the reading device, and the chip threatens to overheat.